Inkjet printers have printheads that operate a plurality of inkjets that eject liquid ink onto an image receiving surface. The ink can be stored in reservoirs positioned within in the printer. Such ink may be aqueous, oil, solvent-based, or UV curable ink or an ink emulsion. Other inkjet printers receive ink in a solid form and then melt the solid ink to generate liquid ink for ejection onto the image receiving surface. In these solid ink printers, the solid ink can be in the form of pellets, ink sticks, granules or other shapes. Typically, an ink loader delivers solid ink pellets or ink sticks placed in the ink loader through a feed chute or channel to a melting device. A reservoir receives the melted ink and supplies the melted ink to one or more printheads. Other inkjet printers use gel ink. Gel inks are also heated to a predetermined temperature to alter the viscosity of the ink so the ink is suitable for ejection by a printhead.
A typical full width scan inkjet printer uses one or more printheads. Each printhead typically contains an array of individual nozzles for ejecting drops of ink across an open gap to an image receiving surface to form an image. The image receiving surface can be the surface of a continuous web of recording media, the surfaces of a series of media sheets, or the surface of an image receiving member, such as a rotating print drum or endless belt. Mechanical force is often used to fix images printed on a continuous web. A spreader nip produces the mechanical force with a pair of rollers configured to apply heat and pressure to the media web.
Continuous feed solid inkjet (SIJ) printers often print roll-to-roll, meaning the printers form images on the media web and then store the imaged media web on a roll for subsequent processing on offline finishing equipment. Such finishing equipment can include devices for, among other things, converting the web into individual sheets, perforating or punching holes into the web, or folding or creasing the web or the converted sheets.
Existing high-speed offline finishing operations, such as conversion into individual sheets, can cause image damage and/or ink offsetting to equipment surfaces. For existing continuous feed SIJ output, this image damage or ink offset can be attributed to insufficient amounts of release agent remaining on the imaged portions of the web. Moreover, the relatively long duration of time between imaging operations and offline finishing operations allows the imaged area to absorb what little release agent remains on its surface. The insufficient amount of release agent on the imaged area enables ink to offset from the web to surfaces of the finishing equipment that contact the imaged area, degrading the performance of the finishing equipment and the quality of the finished image. Systems exist for applying release agent to an imaged media web prior to performing further finishing operations. However, such systems apply release agent to the entire surface of the imaged area without consideration as to whether a given surface of the web is susceptible to ink offset. Consequently, these systems distribute more release agent than necessary since only those areas of a web susceptible to ink offset require treatment. Therefore, efficient application of release agent to imaged areas is desirable.